Difference between revisions of "Display program"
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| − | A '''display program''' is a set of [[instruction]]s for a [[vector graphics]] unit, telling it what to show on the [[display]]. The instructions are stored in [[memory]], often the system's [[main memory]]. | + | A '''display program''', or '''display list''', is a set of [[instruction]]s for a [[vector graphics]] unit, telling it what to show on the [[display]]. The instructions are stored in [[memory]], often the system's [[main memory]]. |
| − | + | Typical instructions are 'display a point' (at a given location), 'display a line' (from one point to another), etc. For display systems with a [[character generator]], there will be instructions to display characters or strings. | |
| − | There is also usually a jump instruction, so that the display can continually [[refresh]], by jumping back to the start of the display program. That | + | There is also usually a [[jump]] instruction, so that the display can continually [[display refresh|refresh]], by jumping back to the start of the display program. Sometimes there are 'jump to [[subroutine]]' and 'return from subroutine' instructions. That allows the display program to be built up out of smaller sections. |
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| + | [[Conditional branch]]es are not usually provided, although in some cases display processors approach general-purpose processors in their capabilities. | ||
[[Category: Device Basics]] | [[Category: Device Basics]] | ||
Latest revision as of 17:51, 30 August 2022
A display program, or display list, is a set of instructions for a vector graphics unit, telling it what to show on the display. The instructions are stored in memory, often the system's main memory.
Typical instructions are 'display a point' (at a given location), 'display a line' (from one point to another), etc. For display systems with a character generator, there will be instructions to display characters or strings.
There is also usually a jump instruction, so that the display can continually refresh, by jumping back to the start of the display program. Sometimes there are 'jump to subroutine' and 'return from subroutine' instructions. That allows the display program to be built up out of smaller sections.
Conditional branches are not usually provided, although in some cases display processors approach general-purpose processors in their capabilities.
